Production of fuel oils



Jan. 26, 1943. E. J. HOUDRY ETAL.

PRODUCTION OF FUEL OILS Filed Feb. 16, 1959 5 R O T N E V m ATTORN EYEUBENELLHDUDRY ALBERT ILFETERKIN BY ,Qtd,

Patented Jan. 26, 1943 UNITED STATES PATENT OFFICE PRODUCTION GF FUELOILS Eugene J. Houdry, Ardmore, and Albert G. Peterkin, Bryn Mawr, Pa.,assignors to Hendry Proeess Corporation, Wilmington, Del., a corporationof Delaware .Application February 16, 1939, Serial No. 256,710

claims. (ci. 19e-5o) v This invention has to do with the conversion ofvery heavy and often almost worthless residual materials into morereadily saleable or useful forms.

Among the materials to be treated are the great quantitiesrof tarry orheavy bottoms in crude oils as well as the residues from reneryoperations on petroleum, from the destructive distillation ofcarbonaceous deposits, etc. Such materials have only a limited sale forsuch uses asroong compounds, road oils, and the like.l

Coking operations are utilized to consume much of the -tarry materialbut the yields of gasoline 875 F. with the preferential range from 810to are low and dimculties and delays are involved due to the frequentshut-downs which are necessary for the removal of the large deposits ofcoke. If the residues are to be disposed of directly as low grade fueloil, they must be blended with very considerable quantities of lightfuel oils or gas oils (which command a good price) in order to meet evenbunker C speciiications. Another expedient is to subject residualmaterial to a thermal viscosity breaking operation which is considerablymilder in character than the previously mentioned coking operations, thepurpose being to convert the heavy charge so far as possible into gasoil for'subsequent cracking and coking operations, but such viscositybreaking producesabout of gasoline of very low grade and octane ratingas well as a lcorresponding or equivalent quantity of gas. Still anotherexpedient is to prepare a vapor phase cracking charge-from such residualmaterial by a contact vaporizing operation which consists in sprayingthe tar in heated condition and mixed with steam or other suitable gasesor vaporsl upon hot highly porous inert contact material and letting thehydrocarbons gradually distill ofi', but this operation calls' for largequantities of steam or the like which must subsequently be removed andin addition lays down coky and resinous deposits in an uneven manner onand within the contact mass, thereby complicating the problem ofregenerating the latter.

One object of the.,-invention is to improve known methods of disposingof very heavy hy.-

drocarbon -residues including those which are solid at room temperature.Another object is to devise a simple and economical way of convertingheavy residues so as to meet fuel oil specilications. Another object isto provide suitable apparatus for eil'ecting the above objects. Still850 F. Feed rates may vary anywhere from 11/2 1 (one and one-halfvolumes oi liquid charge per hour per volume of contact mass) to 10:1.

Suillcient pressure is utilized to keep all of the charge and most ofthe products of the reaction in liquid phase, as up to '150 lbs. per sq.in. Usually, the pressure need not exceed 500 lbs. per sq. in.; and, inmany instances, lbs. per sq. in. is sufllcient. Y The operatingconditions for each type of charge are adjusted so as to produce aslittle naphtha and gas as possible. 'I'he quantity of naphtha recoveredin flashing the product to flash speciiications is normally not over 5%by volume of the charge and, injmost instances, it can be held to 2% oreven less. Residues from asphaltic base crudes usually require somewhathigher temperature and/or lower feed rates than the residues fromparafflnic or mixed base crudes.

The contact material will require regeneration from time to time toremovefthe coky, resinous and other solid or semi-solid deposits whichaccumulate in the pores during the operation, hence for continuousoperation two or more con# tainers or converters are utilized, so thatat least one converter maybe on stream while the other or others are inregeneration. Any suitable form of regeneration may be utilized, burningbeing the most effective, with purging operations before and after by avaporous medium or by vacuum and with occasional ilushing with a solventafter the burning operation, if desired. As

a preliminary step to regeneration, it is usually advantageous to lsendthrough-the converter a quantity of lighter` hydrocarbon material, suchas a gas oil, for example, in :an amount substantially equal to thevolume of the contact mass, to wash out of theconverter the heaviercharge. Such washing material is preferably sent through the converterunder the pressure of the operation, the pressure then being released topermit the gas oil 4or other lighter hydrocarbon material to vaporizeand leave the converter. This step is not only important in preventingloss of charging material, but the wash oils may be incorporateddirectly with the products of the operation to make such adjustment asmay be necessary to meet the desired fuel oil specifica,- tions. Thequantity of lighter material needed for this purpose is readilydetermined during the usual laboratory tests which precede plantoperations.

In order to illustrate the invention and the manner of its use, oneconcrete embodiment of apparatus for practising the same is indicatedsomewhat diagrammatically in the single figure of the accompanyingdrawing. The heavy residual material, heated sumcientlv to be fluid, isforced by pump I, which imposes enough pressure on the charge to retainit and subsequent products in liquid phase condition, as from 100 to 300pounds per square inch, through a heater coil 2, where its temperatureis raised to within the reaction range of approximately '775 to 875 F.'Ihe rate of feed through coil 2, however, is made sufficiently high,within the range of 11/2z1 to 10:1, with due consideration to thecharacteristics of the charge, so that thermal cracking is substantiallyor practically avoided. The heated charge then passes by valved line 3into the lower manifolding chamber 4 of converter 5, and is forcedupwardly through the perforations in lower partition member 6 into andthrough the large central reaction chamber 1 which is completely lledwith a mass M of highly porous solid contact material, in the form ofbits, fragments or molded pieces, having little or no catalyticactivity. The contact material may be silicious in character and may beformed after the manner disclosed in U. S. Patent No. 1,818,403, issuedto Alfred Joseph on August l1, 1931. A similar material which is lessinert in character may be prepared by taking about 90 parts of activatedclay, such as California Superflltrol, with about l parts of aplasticizing medium such as Argosite (trade name for a highswelling'bentonite) to give strength, and with about 70 parts ofmaterial to product porosity, such as corn meal, these partsbeing-'thoroughly mixed and extruded inte 4 mm. pellets which are thenheat treated to produce the desired low degree of catalytic activity,during which treatment the corn meal is burned out to give a high degreeof porosity in the pellets. The products of the reaction pass fromreaction chamber 1 through perforations in upper partition member 8 intoupper manifolding chamber 9, whence they pass by valved branch I 0 intoproducts line Il leading through cooler IIa to a flashing zone providedwith flashing equipment of any known or suitable type, such as tower I2.Stripping steam may be sent into the lower part of tower I2 by line I3,this steam escaping with the released naphtha and gas through overheadline I 4, while the fuel oil, preferably adjusted to flashspecifications, issues from tower I2 by bottom outlet line I5.

To insure accurate temperature control of contact mass M ln converter 5,a heat exchange and an outer manifold member IIb with which the outerconduits I 6b connect. The heat exchange circuit further consists of aheat exchanger |8 and a pump I9 for circulating the heat exchangemedium, which may be a fluid of any suitable or desired type, eithergaseous or liquid. With the temperatures for the present operation,liquids such as water, fused salts, mercury, diphenyl, or metals ormetallic alloys having low melting points, are most suitable. The heatexchange medium supplies heat to contact mass M, during the on-stream orviscosity breaking operation, to maintain the entire mass at suitabletemperature, and extracts heat from the mass during the alternatingregenerating period, when the deposit on the mass is burned away toprepare for another on-stream operation.

After a suitable period of operation, the charging of heavy bottoms isinterrupted in order to regenerate contact mass M. As a preliminary stepto the regeneration, the mass is purged of the charge. This may beeffected by sending steam into the case. as through upper valved branchline 20, the dislodged fluid being vented through a lower valved line 2|serving as a drain. However, if the charge to be converted is veryheavy, or if the viscosity breaking has not been sufficient to meet fueloil specifications, it is advantageous to adjust the products by washingout the converter with a lighter hydrocarbon material, such as a gasoil, which may be charged to the converter under the same or similarpressure and temperature conditions. In many insystem is provided,consisting of nested heat exchange units I6 embedded in the contact massM in symmetrical arrangement throughout the entire reaction zone, eachunit consisting of an inner conduit Ilia and an outer conduit I6b whichmay be provided with fins (not shown). The conduits connect withmanifold units I1 in upper manifolding chamber 9, which manifold unitscomprise an inner manifolding member Ila. supplying inner conduits Itaof nested units I6,

stances, only a limited amount of such wash oil is needed, as, forexample, an amount approximating the volume of contact mass. While suchgas oil used for the washing medium can be sent through the pump andheating equipment fox-the normal charge, it is preferable to utilize aseparate pump 22 and coil 23, which coil may be in the same heater orstill as coil 2, as indicated in the drawing, or in a separate heater.The pressure and temperature conditions are preferably identical or atleast similar to the operation with the heavier charge. The heated washoil then passes by valved branch 24 into and through converter 5, andthence to ash tower I2 in the same manner as the normal charge. The washoil may be mingled with the charge during .the period in which thelatter is being shut off from the converter. Alternatively the gas oilmay be introduced at the top of the converter, as by line 20, todisplace the contents of the converter through line 2I to pass intoproducts line II before cooler Ila, by suitable cross-over connections(not shown). After this limited washing operation, the pressure inconverter 5 is released and the converter is permitted to drain bygravity into a suitable tank or container (not shown) to recover allhydrocarbons which will leave as vapor or as liquid. The converter isthen steamed or subjected to vacuum purging, as through line 20, andthereafter a regenerating medium, such as air or other oxygen containinggas, is sent by line 25, preferably in heated condition and underpressure, to effect controlled burning of the deposit on the contactmass M, the fumes escaping through valved branch line 26 from the upperend of the converter. After the burning operation is completed, theconverter is again purged by steam or by vacuum, and is ready to be putback on stream for another viscosity breaking operation. From time totime, it may be necessary, as a final stage in the regeneratingoperation, to utilize inlet line v2l) and drain 2| to eiect solventwashing of the mass M by water, dilute acids. or other media, to extractfrom the mass salts or other contaminants which cannot be removed by theburning operation, as disclosed, for example, in Patent No. 1,957,649,issued May 8, 1934, to Eugene Houdry. i

While it is possible to operate the process with a. single converter.such as 5, there are obvious advantages in conducting the viscositybreaking operation as a continuous process. To eiect a continuousoperation, two or more converters 5 will be necessary, so that one o1-more may be utilized for the viscosity breaking operation while theother or others are in regeneration. To indicate continuous operation,two converters 5 are shown in the drawing, but the second requires nodetailed description, since it is a mere duplication of the other. Theconverters 5 and the various lines will be lagged or J'acketed'toprevent heat losses, but such obvious expedients are not indicated,since they form no part ofthe present invention.

The use of the invention in handling very heavy residual chargingmaterial is illustrated bythe following examples:

Example 1 An 8.1% tar bottoms from a mixture of Mid- Continent and EastTexas crudes had the following characteristics:

Flash P. M. C. C F 225 Say. U. Vis. at 210 F 734 Pour point, F +110Gravity, A. P. I 12.6

To bring the above -material to bunker C speciiications, it was foundnecessary to add 54 parts ditions .to Wash out the converter; theproducts of the gas oil washing were added to the products of theviscosity breaking operation to give 102 parts of fuel oil of' thefollowing characteristics:

Flash, P. M. C. C 154 Furol viso. at 122 F 159 Pour point, F +25Gravity, A. P. I 14. 5

There was also produced:

2.1% by volume of naphtha (recovered by ashing -to flash specifications)1.5% by weight of gas oi 1.12 sp. gr.

0.4% by weight of coky deposit which was burned oilr in the subsequentregenerating opertion.

Hence by employing the viscosity breaking o'peration, there was effecteda net saving of 49 parts of gas oil (54 parts without viscosity breakingas comparedr with 5 parts after viscosity breaking) per 100 parts oftar.

The gas oil used for blending purposes was recycle stock from a crackingoperation on a blend of East Texas crudes.

Example 2 A 32% tar bottoms from Venezuelan (Lagunillas) crude had thefollowing characteristics:

Say. U. Vis/210 F T-- Too heavy. Pour point Over (+120). Gravity 3.4.

To bring this material to bunker C specifications, 122 parts of gas oilper 100 parts of tar were needed.

The tar without steam or other added material was subjected to thecatalytic viscosity breaking operation at 840 F. temperatureand under apressure of 300 lbs. per sq. in., at a feed rate of 2:1 for a two hourperiod. Only 31 parts o1 gas oil were then needed per 100 parts of tarto make 125 parts of bunker C fuel oil, a part of this gas 20 oilequivalent to the catalyst volume of lthe converter being chargedthrough the latter under the specified operating conditions to free thecontact mass of the heavy charge. The blended fuel oil product had thefollowing characteristics:

Flash, P. M. c. c F. 156 Furo1visc./122 F 147 l Pour point, F +20Gravity; A. P. I 9.8

There was also produced:

1.6% by volume of 62.0 A. P. I. naphtha (recovered by flashing to ashspecifications) 4.6% by weight of gas (1.15 sp. gr.)

2.4% by weight of .coky deposit to be burned of! in the subsequentregeneration of the contact mass.

` By 'using viscosity breaking, a saving of 91 parts of gas oil (122parts without viscosity 40 breaking as compared with 31 parts afterviscosity breaking) was effected. I

From the above, it will be apparent that the present invention providesa simple and economical method of converting substantially worthlessheavy residual material into salable fuel oils, without the problem ofdisposing of large quantities of petroleum coke. By utilizing two ormore converters, a continuous operation is effected without anynecessity of frequent dismaitling to clean out the reaction chambers, asis required in conventional thermal coking plants. The process operateswith a high charging rate, and produces only a relatively small amountof coke which is immediately burned during the alliberated not beingwasted, but being directly recoverable in the forms of power, heat andsteam. The contact mass filters out sediment, and is highly efiicient asa selective viscosity breaking agent, since so little naphtha, namely,of the or der of A2% by volume, is recovered. The contact mass alsolocalizes the deposition of coke on the contact mass whence it isperiodically removed by burning, prevents its deposition andaccumulation in pipes, valves and other parts of the equipment, and soenables continuous uninterrupted operation under wide variation ofoperating conditions. Definite and practical advantages reside in theuse of gas oil both as washing medium and as a medium for 'effectingfinal adjustment of the products 'to fuel oil specifications; its use,however, may be minimized or even entirely avoided by recirculating orrecycling a part of the products, or by making a less deep 75 cut whenthe original charge is prepared.

Flash, P. M. c. c 380 F.

ternate regenerating operations, the energy thus We claim as ourinvention:

1. In the conversion of tars and similar residues into commercial fueloils, the process steps which comprise sending the charge in heatedcondition and in liquid phase through a reaction chamber containinghighly porous silicious contact material of low catalytic activity,maintaining the chamber under suflicient pressure to insure liquid phaseoperation, holding the contact material at conversion temperature andadjusting the feed rate to produce only'a small quantty of naphtha,after a period of operation substituting for the heavy charge a quantityof lighter hydrocarbons in the gas oil boiling range substantiallyequivalent to the volume of the contact mass and'sending it through thereaction chamber under the same operating conditions to flush thecontact mass as a preparatory step to regenerating the same, limitingthe on-stream operation with heavy charge to such a period that thecombining of the products of the heavy charge and of the substitutecharge meets fuel oil specifications, mingling the products of bothcharges to form a commercial fuel oil, then freeing the contact materialof coky, resinous and other deposits by a regenerating operation, andrepeating the above steps.

2. In the conversion of .tars and similar residues into commercial fueloils through the action of solid porous contact material which has to befreed from time to time of coky and resinous deposits in order that theconverting reaction may be continued, the process steps which comprisesending the charge in heated condition and in liquid phase through areaction chamber containing the porous contact material, maintaining thechamber under a pressure of at least 100 lbs. per sq. in. during theon-stream operation, holding the contact material at a conversiontemperature.

and adjusting the -feed rate to produce only a small quantity of naphthaand finally adjusting the products of the reaction to meet fuel oilspecifications by substituting for the charge a predetermined quantityof lower boiling oil which is sent through the reaction chamber underthe same operating conditions and is added to the aforesaid products,and then regenerating the contact material in preparation for anotheronstream operation.

3. In the conversion of tars and similar residuessinto commercial fueloils through the action o-f solid porous contact material, the processwhich comprises ending the charge at a temperature at least as high as775 F. in liquid phase and under pressure through a reaction zone lledwith the porous contact material at such rate as to produce only a smallquantity of naphtha, continuing the feeding of the charge until thereaction is impaired by the deposition of coky, resinous and othercontaminants on the contact material, and then prior to regenerating thecontact material by oxidation feeding to the reaction zone a limitedquantity of oil in the gas oil boiling range to act as a flushingmedium, and addlng the resulting hydrocarbons to the products of theon-stream operation to adjust the same to meet mel oil specications;

4. In the conversion of tars and similar residues into commercial fueloils through the action of solid porous contact material, the processwhich comprises sending' the charge in heated condition and undersuilicient pressure to maintain it in liquid phase through a reactionzone filled with porous but substantially inert contact material andmaintained within the temperature range of 810 to 850 F.; adjusting thefeed rate with relation to the gravity and other characteristics of thecharge so that the reaction produces only a small quantity of naphtha.continuing the feeding of the charge until the reaction is impaired bythe deposition of coky. resinous and other contaminants 'on the contactmaterial, then changing the charge to lower gravity hydrocarbons of thegas oil type but maintaining the same operating conditions, limiting thequantity of such lower gravity hydrocarbons to an amount requisite toflush the contact mass as a preparatory step to regenerating the sameand to adjust the products of the reaction to fuel oil or Bunker Cspecifications, and mingling the products of both changes to form acommercial fuel oil.

5. In the conversion of tars and similar residues into commercial fueloils through the action of solid porouscontact material which has to befreed from time to time of coky and resinous deposits in order ,that theconverting reaction may be continued, the process steps which comprisesending the charge in heated condition and in liquid phase through areaction chamber containing the porous contact material, maintaining thechamber under a pressure of at least 100 lbs. per sq. in. during the onstream operation, holding the contact material at a conversiontemperature and adjusting the feed rate to v said first reaction chamberto flash of! the lower boiling oil, regenerating the contact material insaid rst reaction chamber by freeing it of coky and resinous deposits,then restoring the feeding EUGENE J. HOUDRY. ALBERT G. PETERKIN.

